Clamping device



No 17 1936' PRENDERGAST ET AL 06123769 CLAMPING DEVICE Filedocr. 2o, 1952 n y 2 Sheets-Sheet l` Patented Nov. 17, 1936 UNITED STATES PATENT OFFICE VCLAMPING. DEVICE Jamesv Prendergast and: `loseph Prendergast,

Claremont, N. H.,; assignorsfto Sullivan'Machnery Companygacorporation of Massachusetts Application octeber 2o, 1932, serial No. 633,823

claims. (c1. 81-17) l clamping mechanism. A`further object of our\ veniently moved to them, because heating of the castings in grinding them necessitates interruption of the grinding operation until the pieces 'to be ground, cool. Moreover, the stationary grinders cannot handle large-castings, for these cannot be brought within their range of operation. `Swing-frame grinders have therefore been used in conjunction Withstationarygrinding wheels, these swing-frame grinders including a motor andy a grinding wheel with a transmission connecting the two, the whole being balanced and suspended fromy above. rThese swing-frame grinders, however, have not, heretofore, lreadily been usable with small castings; and larger castings, too small to be held stationary by their own weight, but large enough to causethe use of the swing-frame grinder instead of stationaryl grinding wheels, havepresented' a troublesome problem in holding themv stationary so that the swing-frame grinders could be used-with them. Two general methods have been employed in positioning `such castings for grinding, including 'bench'. and also the bedding of the castingslin I sand boxes mounted on benches; ybut neitherof these arrangements has been entirely satisfactory, the blocking method requiring excessive time and the sand bed method not insuring ythe holding of the castings stationary.

Our invention. hereinafter described, makes it possible to `employ a swing-frame grinder for practically all castings below that size Where the andV supporting the castings with blocks upon a low` mere mass of the casting itself willhold it'sta.-r

invention is to provide an improved pressure fluid operated vise adapted readily to hold a'wide variety of vdifferently shaped; objects. Another ob- `jectoi' our invention is toprovide anrimproved pressurev fluid operated clamping mechanism having Vadaptability to a wide range of sizes Ain the objects to be gripped. A still further object of `our invention is Vto provide an improved vpressure iiuid operated clampingmechanism particularly adapted touse with swing-framelgrinders and adapted to be as free as possible from impediment in operation by depositsof the ground materialupon its bed frame. Other'objectsand advantages of our invention will hereinafter more fully appear.

In the accompanying drawings, in'whch vone form of our invention is shown forpurposes of illustration,`- w

,Fig '1f isaplan viewof the improvedclamp with parts broken away;

Fig. -2 is a verticalsection on the line 2-2 of Fig.,1, withparts broken away; f' 1 f Fig. 3 is an end view from the right handend vof Figs. 1 andZ, with parts broken away;

Fig. 4 is an enlargedview of the clamping jaws,

Fig. 5 is an elevational view of the adjustable clamping jaw.. l f

. Referring to thedrawings, -itwill be observed thatend vpedestal or bracket frame membersv I and 2 support a suitable strong, fiat; horizontal bed platemember 3. Beneath the bedplate member, and extending herein from a'pointadjacent one end thereof,ras far as maybeidesired toward the other end thereof, is a suitable heavy reenforcing member 4; andthe bedqplate 3"and` reenforcing member 14 are traversedby a, series ofholes 5, 5, whose axes'lie in avertical plane extending `approximately .centrally of the rbed platefor a substantial*distancemThese lfopenings 5, 5 are adapted to receive a cylindrical supporting projectiona carried by anV vadjustable jaw member 1 and about which the jaw member ispi'votable into any desired position completely as to provide a plurality of projecting gripping portions adapted to cooperate with work held between the jaw member 1 and its cooperating jaw.

Cooperating with the stationary jaw is a movable jaw member I5 having a concave work engaging :portion IB provided with corrugations or other work engaging projections` I1. cave portion I5 of the jaw member I5 may advantageously be formed so as to ilt with the convex side I2 of the adjustable jaw member 1.

The movable jaw member I5 is provided witha pair of feet I8 arranged near its opposite ends and adapted to maintain vthe jaw horizontal, these feet supporting the jaw member I5 in the same horizontal plane with the jaw member 1 and, as a result o! their small surfaces in contact with the beo. plate 3, permitting a minimum interference with the motion oi.' the jaw, due to possible deposits oi.' grindings, or the like, upon the bed plate 3. Thev jaw member I5 is pivotally connected at I9 with a piston rod Zlwhich will shortly be further described. The pivotal connection I9 provides a limited motion between the jaw member and piston rod, permitting the Jaw member I5 to adapt itself, through a limited lateral `turning motion, to peculiarities in shape of members to be gripped. .The jaw member 1 is free to move into any desired position about its pivotal mounting while the jaw member I5 has relatively limited pivotal movement.

For the purpose of reciprocating the piston rod 20, `we have provided an air motor, which may be of any suitable form, and which is generally designated 2I and comprises herein a cylinder member 22 having opposite cylinder heads 23, 24, herein respectively having feet 25, 23 supporting themotorupon the bed plate and held in position by screws or bolts 21. Obviously, a single foot Aat either end of the motor would be adequate, if preferred. Suitable side rods 2l hold the cylinder heads in engagement with the cylinder member 22. Within the bore 23 of the cylinder member 22 a piston 30, having suitable packing 3|, is reciprocable, and to the piston 3II the piston rod 20 is rigidly connected.

Air from a suitable source of supply is admitted to the opposite ends oi the motor 2| through connections 33, 34 under the control of a tourway valve 35, this valve receiving air through any suitable connection, not shown, at itsV supply opening 36, and being adapted to vent air as may be desired through a discharge opening 31. Thepiping or the valve may be so constructed as toprevent excessive speed oi motion of the piston 30, and accordingly of the jaw member I5, as by providing relatively large check-valve-controlled vent passages and small supply passages,

or by the use of any suitable iiow controlling` restrictions, if that be preferred. 4A suitable operating handle 38 is provided for moving the four-way valve to admit air to either end oi' the clamping motor 2l while venting the other, as may be desired. f

Themode of operationoi our invention will be readily understood. vA grinder operator having a-casting to be ground will position the adjustable jaw 1 in such relation to the limit of travel of the power-moved. jaw I5 that the piece to be ground may readily be gripped. Whichever side ofthe jaw member 1 will most advantageously cooperate with the jaw member I5 in clamping the piece to be ground, will be turned toward the jaw member I5. The piece to be ground will' then be positioned against the `jaw 1 and air will be admitted by movement of the handle 38 to a suitable position to admit air at the desired rate through the connection 34 to the right hand end of the clamp operating cylinder 2I. The four-way valve mechanism 35 will simultaneously vent the opposite or left end of the motor cylinder 22. The clamping jaw member I5 will then move over into engagement with the piece to be held and will. clamp the latter ilrmly between the jaw members 1 and I5, the member I5 turning, if necessary, as permitted by its pin connection I9, to'adapt itself to the shape of the work piece, and the jaw member 1 pivoting as is necessary to insure a rigid, multi-point clamping engagement of the casting to be held. It will be understood that the casting to be ground may advantageously rest upon the bed plate between the jaws and will be held immovable by the latter, and accordingly the grinding wheel of the swing-frame grinder may be pressed with all the force consistent with proper operation which the grinder operator may bring to bear. It will be understood that when some of the surfaces requiring grinding have been ground, the work piece may be released merely by moving the valve operating handle 3B to cause the piston 30 to move to the right, and when the work piece has been adjusted to its new position, the jaws may be again caused to grip it.

It `will be understood that the bodily adjustability of the jaw member 1, its reversibility, and the capacity for angular movement which it possesses will, in conjunction with the powermoved and slightly 'angular-ly adjustable jaw member I5, permit the clamping of an almost unlimited variety of shapes, and in a wide range of sizes, with absolute safety. It will be appreciated, moreover, that with this clamping mechanism, the fixing of va casting in the position to be operated upon is a matter of seconds, rather than a matter of minutes or more with the bench and block system, and that the pressures which can be applied and the speed of the grinding operation may be much increased. It will be observed, moreover, that the mechanism is relatively inexpensive, and that it is adaptable to many other uses besides that of a foundry, although the foundry use is of particular importance.

While we have in this application specifically described one form which the invention may assume in practice, it will be understood that this form' is shown for purposes of illustration and that the invention may be modied and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What we claim as new and desire to secure by Letters Patent is:

1. In a vise, a jaw member having a pin adapted to support the same against displacement and having relatively small depending feet at opposite ends thereof.

2. In a vise, a jaw member having a pin adapted to support the same against displacement but providing for angular movement about the axis of said pin, and having relatively small depending feet at opposite ends thereof for supporting the same in different positions thereof.

3. In a vise, a bed, a jaw member movable along the bed and comprising a body portion spaced from the bed along which it is adapted to be moved, an actuating connection therefor, and at least one foot for supporting and guiding said jaw in spaced relation to the bed, and a second jaw member on said bed and with which said iirst Jaw cooperates during the clamping operation.

4. In a vise, a bed, a jaw member movable along the bed and comprising a body portion spaced Y from the bed along which it is yadapted to be moved, an actuating connection therefor, and. relatively small feet at opposite sides of said wm nection for guiding said jaw member with its body portion in a constant angular relation to the plane of the bed, and a second jaw ymember' on said bed and. with which said first jaw cooperates during the clamping operation.

5. In a vise, a bed, a jaw member movable along .the bed and comprising a body portion spaced from the bed along which it is adapted to be moved, actuating means therefor including an actuating connection permitting pivoting Ain planes parallel to the bed but precluding pivoting in places at right angles to said iirst mentioned planes, and relatively small feet at opposite sides of said connection for guiding said jaw member with its body portion in a constant angular relation to the plane oi the bed, and a second jaw member on said bed and with which said rst jaw 10 cooperates during the clamping operation.

JAMES PRENDERGAST. JOSEPH PRENDERGAST. 

